For the uninitiated (which included me until a few months ago), a jim crow is a device used by permanent-way gangs to bend track (see - http://en.wikipedia.org/wiki/Jim_crow_%28tool%29 ).
It seems surprising to me that, as far as I know, no one has produced one commercially for use on garden railways - particularly for code 332 rail which is extremely difficult to bend but is often used for G scale railways (eg LGB, Piko, Trainline, etc.).
Fortunately, one of my fellow modellers on the G Scale Central forum has the engineering skills and equipment needed to produce them and for a small fee made one for me.
I modified his original design slightly by drilling out a couple of slots either side of the screw thread to accommodate the chairs on the sleepers (ties) on LGB track which are quite prominent.
There were several places on my railway where rail-joints on curves were not as continuously smooth as I would have liked: for example ........
It is for situations such as these that the jim-crow comes into its own. The jim crow was slotted over the rail about four or five sleepers away from the offending joint ........
... and the screw tightened until it engaged with the edge of the rail. I then tightened the screw a further half-turn - thus bending the rail slightly (the lower rail in the picture below now has a slight bend).
This process was repeated, moving the jim crow one sleeper nearer the joint each time and each time adding one more half-turn (or sometimes a quarter turn if the kink at the joint was not too severe). This introduces a gradually increasing curve to the rail as it nears the joint.
If you compare these two pictures with those showing the kinks above, you can see the difference.
The amount of bend can be tailored to suit each location - and if it turns out that I have made the curve too severe, the jim crow can be slotted on the opposite way round and tightened up to ease the curve.
Whereas previously, I had several locations where the rail-joints had some quite alarming kinks - partly due to my poor track laying but also due to the ravages of heat and cold on the track - I now have much smoother curves - which both my eyes and the rolling stock greatly appreciates.
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| Jim crow rail bender (Source: http://www.indiamart.com/universal-jacks-mfg/mechanical-screw-jack.html) |
It seems surprising to me that, as far as I know, no one has produced one commercially for use on garden railways - particularly for code 332 rail which is extremely difficult to bend but is often used for G scale railways (eg LGB, Piko, Trainline, etc.).
Fortunately, one of my fellow modellers on the G Scale Central forum has the engineering skills and equipment needed to produce them and for a small fee made one for me.
I modified his original design slightly by drilling out a couple of slots either side of the screw thread to accommodate the chairs on the sleepers (ties) on LGB track which are quite prominent.
There were several places on my railway where rail-joints on curves were not as continuously smooth as I would have liked: for example ........
It is for situations such as these that the jim-crow comes into its own. The jim crow was slotted over the rail about four or five sleepers away from the offending joint ........
... and the screw tightened until it engaged with the edge of the rail. I then tightened the screw a further half-turn - thus bending the rail slightly (the lower rail in the picture below now has a slight bend).
This process was repeated, moving the jim crow one sleeper nearer the joint each time and each time adding one more half-turn (or sometimes a quarter turn if the kink at the joint was not too severe). This introduces a gradually increasing curve to the rail as it nears the joint.
If you compare these two pictures with those showing the kinks above, you can see the difference.
The amount of bend can be tailored to suit each location - and if it turns out that I have made the curve too severe, the jim crow can be slotted on the opposite way round and tightened up to ease the curve.
Whereas previously, I had several locations where the rail-joints had some quite alarming kinks - partly due to my poor track laying but also due to the ravages of heat and cold on the track - I now have much smoother curves - which both my eyes and the rolling stock greatly appreciates.
1 comment:
So Easter seven years ago you were sorting this. I am going to have a go at making a Jim Crow. John
https://youtube.com/playlist?list=PLYcygI36v6pRaINQ467TDN4ZElCOoypRO
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